Portable devices that include a processor and storage are well known in the art. One example of such devices is the IC card or smart card, but many other portable devices including a processor and storage are well known.
Some portable devices are useable in ways which are particularly valuable. An example of a particularly valuable use is a use in monetary transactions; for example, certain types of smart cards may be used to authorize a monetary transaction or may be used to store monetary value that is useable in a monetary transaction. One example of a stored value smart card is the Mondex card, which is described, for example, in one or both of the following World Wide Web (WWW) sites: www.mondex.com; and www.mondexusa.com.
Another example of a particularly valuable use is a use in a service related transaction; for example, in a card such as a smart card which provides conditional access services.
For purposes of simplicity of description, the term “monetary transaction” is used throughout the present specification and claims to include both monetary transactions and service related transactions.
It is known in the art to provide conditional access or user authorization to portable devices which are particularly valuable.
U.S. Pat. No. 5,515,031 to Pereira et al describes a credit card detector and validator which detects non-return of a credit card to a user, or return of an incorrect credit card to a user.
PCT published patent application WO 98/27519 describes an improvement to credit cards, in which a verification device separate from the credit card is used. Data is read from the verification device at the time that a transaction is carried out, ensuring that the verification device is related to the credit card.
U.S. Pat. No. 5,648,647 to Seiler describes an anti-fraud credit card dispatch system in which a time sequence at a point of sale verifies possession of both an old credit card and a new, replacement credit card.
U.S. Pat. No. 5,585,787 to Wallerstein describes a programmable credit card which allows access to one of a plurality of different credit accounts.
U.S. Pat. No. 5,590,038 to Pitroda describes a universal electronic transaction card which may serve as a number of different credit cards, identification cards, or other cards.
U.S. Pat. No. 5,748,740 to Curry et al describes a module used for secure transactions, the module being capable of being programmed, keeping track of real time, recording transactions for later review, and creating encryption key pairs.
U.S. Pat. No. 5,468,941 to Sasaki describes money processing apparatus including, in addition to money feeding a storing, data and time apparatus.
U.S. Pat. No. 5,511,121 to Yacobi describes an electronic cash system which takes advantage of a property of the El Gamal signature scheme.
U.S. Pat. No. 5,602,919 to Hurta et al describes a system for monetary transactions including a smart card and a smart-card-based transponder.
U.S. Pat. No. 5,715,926 to Furneaux et al describes apparatus for validating items of value, such as money.
Hash functions and other cryptographic functions that may be useful in the field of providing conditional access to monetary transactions are described in: Bruce Schneier, Applied Cryptography, Second Edition, John Wiley & Sons, Inc., 1996.
The disclosures of all references mentioned above and throughout the present specification are hereby incorporated herein by reference.